[1] Ministry of Water Resources Development, P.O. Box 5744 or 5673, Addis Ababa, Ethiopia
[2] School of Graduate Studies, Haramaya University, P.O. Box 138, Dire Dawa, Ethiopia
[3] International Water Management Institute, Africa Regional Program, CT 112, Cantonments, Accra, Ghana
[4] Agricultural Economist, Oromia Agricultural Research Institute, P.O. Box 265, Oromia, Ethiopia